And it would be nice to see a 'movement' take hold that would make all of these lazy manufacturers sit up and take notice that they are peddling quite a lot of unsustainable crap these days. To many people, buying much of this gear is a big investment, a leap of faith in the integrity of such large companies. Not all of the buyers have the experience to know whether they do or do not find themselves in possession of a lemon; that they are unaware isn't any excuse behind which the makers should be able to hide.

I suspect that part of the problem is too wide a gamut of objectives: too many models diluting the TLC that should be available within the factories. Let true professional equipment be expensive if it must - it's usually deductible to the pro and the rich am. can buy it easily - do we really need so many in-between models cluttering a range? I think not. It would make more sense for there to be three basic types: top, mid-range and beginner, with the lesser family members offering a useable range of functions, not a war chest of probably unused fantasies few need or probably even know they have bought. Manuals are far too big already!

The number of people complaining of poor copies with decentering, smearing etc.

I guess there is a possibility that this particular lens has been checked out particularly rigorously, given the very high expectations generated by the reviews. I am not defending poor quality control here, just wondering whether the lens is actually exceptionally bad.

Modern lenses are hella complicated, so maintaining QC becomes problematic. Not to mention that modern sensors demand much more and reveal flaws more than film did (at least in 35mm film). Question is, do you want to have to pay Leica prices for your Canikon glass? QC ain't free.

Modern lenses are hella complicated, so maintaining QC becomes problematic. Not to mention that modern sensors demand much more and reveal flaws more than film did (at least in 35mm film). Question is, do you want to have to pay Leica prices for your Canikon glass? QC ain't free.

This is in line with my suggested policy for these companies: streamline the line, and so yes, when I was working, a resounding Yes!

Hassy lenses were always premium priced, and there were no substitutes; didn't hold them back in the day, and I was happy to use them too!

Now, retired? The truth? Were there no alternative, then I would still be buying at what I thought to be top grade. But since there are so many 'cheaper' options around, I cut corners and buy a D700 instead. Having said which, it is all the camera I seriously require for anything I'm likely to do. But it doesn't make me feel fantastically good about myself; there's no F or 500C/M buzz there. Not a whiff of it.

Hell, if the image quality and quality control were of the highest order I'd pay Hasselblad prices.

Maybe you would, but it is highly doubtful that most Sigma/Nikon/Canon customers would be willing to pay the hefty price associated with the kind of tighter tolerances required to ensure that any sample has a 99.99% chance of being tested as perfect by the most demanding tester.

There is also the problem of camera-body quality control. What I find curious is that my Sigma 35/F1.4 doesn't require any autofocus fine tuning at all on my D800E, yet it requires the maximum adjustment of +20 on my D7100.

On the other hand, my Nikkor 24-120/F4 zoom doesn't require any autofocus fine tuning at all on my D7100, yet requires a modest amount of adjustment on the D800E.

I'm thankful that the maximum adjustment appears to be sufficient to allow me to get sharp results using autofocus with the D7100 because it's too late to return the lens. You can see from my very elaborate test procedures in attached images that the +20 adjustment appears to have done the trick. The images are at F1.4.

Unfortunately, this terribly sophisticated test target is not for sale.

There is also the problem of camera-body quality control. What I find curious is that my Sigma 35/F1.4 doesn't require any autofocus fine tuning at all on my D800E, yet it requires the maximum adjustment of +20 on my D7100.

On the other hand, my Nikkor 24-120/F4 zoom doesn't require any autofocus fine tuning at all on my D7100, yet requires a modest amount of adjustment on the D800E.

I'm thankful that the maximum adjustment appears to be sufficient to allow me to get sharp results using autofocus with the D7100 because it's too late to return the lens. You can see from my very elaborate test procedures in attached images that the +20 adjustment appears to have done the trick. The images are at F1.4.

Unfortunately, this terribly sophisticated test target is not for sale.

I don't own the Sigma lens but have been interested in buying it. Two years ago I bought the Zeiss 35mm f2 in Canon fit. It is an exceptional lens in every way except one. It's manual focus, and as I like using it wide open quite often, I do have trouble focussing the damn thing. In live view mode on a tripod it is great - but hand-held I do struggle. Hence considering the Sigma.

Ray, I did read an interesting article a while back on the subject of manufacturing tolerances. Your problems are just to be expected in regard to different lenses on different cameras - It's just a matter of tolerances, and how they interact with each other - some you win, some you loose.

And to some of the other comments here regarding problems with the Sigma lens - you just have to realise that it is built to a budget and will not compare to say, a Leica lens. Not that the lens is low-quality, just that there will be a greater range of tolerance accepted by quality control. And curvature of field affecting a lens at different focussing distances, de-centred lens elements, and focus-shift when using very wide aperture lenses are all problems for most lenses - not just the Sigma.

Makes sense to me. Look at what we've seen transpire in the American automobile industry. The Ford Motor Company phased out the Mercury line and in the process created better identities for its Ford and Lincoln products: General Motors shucked off the largely duplicative and overlapping Pontiac and Oldsmobile lines. Coming out of the recent American recession, both companies are stronger than they were five years ago. I like the idea of reducing the range of models and doing a better job of refining how they work and defining what/who they're for. These days there's a lot of too-similar products, and that could be distracting and inefficient to make and manage, as well as to choose between for the consumers.

simply best optical quality on Nikon d800 at wide open, fantastic at 5,6-8.AF works only at the center and at close, very close distance. AF simply not usabele, I focus manual, its work. It should be sell as an manual focus lens.

My take on this lens is that the problem is with the number of elements. In theory it should be a highly corrected masterpiece. The advantage of a prime used to be that the simple design with few elements did not allow too many errors. Fewer surfaces, each with their own errors, fewer reflections, fewer spacing jig errors, etc. This lens is just too complex.

simply best optical quality on Nikon d800 at wide open, fantastic at 5,6-8.AF works only at the center and at close, very close distance. AF simply not usabele, I focus manual, its work. It should be sell as an manual focus lens.

My take on this lens is that the problem is with the number of elements. In theory it should be a highly corrected masterpiece. The advantage of a prime used to be that the simple design with few elements did not allow too many errors. Fewer surfaces, each with their own errors, fewer reflections, fewer spacing jig errors, etc. This lens is just too complex.

My take is that there is zero problem with this lens. It a masterpiece that will remain as a landmark similar to the Canon 70-200 f2.8 II, Leica 180 f2.8 APO, Nikkor 85mm f1.8 AF-S, Zeiss 55mm f1.4,...

The fact that a few samples had quality control issues doesn't change anything.

My take is that there is zero problem with this lens. It a masterpiece that will remain as a landmark similar to the Canon 70-200 f2.8 II, Leica 180 f2.8 APO, Nikkor 85mm f1.8 AF-S, Zeiss 55mm f1.4,...

The fact that a few samples had quality control issues doesn't change anything.Cheers,Bernard

My take is that there is zero problem with this lens. It a masterpiece that will remain as a landmark similar to the Canon 70-200 f2.8 II, Leica 180 f2.8 APO, Nikkor 85mm f1.8 AF-S, Zeiss 55mm f1.4,...

The fact that a few samples had quality control issues doesn't change anything.

Cheers,Bernard

Maybe. It seems like a lot more people in this thread said they had problems compared to the % that said theirs was great.

Kudos to Sigma for offering this. But...it's precisely the need for this kind of tweak-o-rama that led me to abandon phase-detect AF systems. How 'bout D-SLR makers offer a PD-AF mode in which focus is actually verified? Is this too much to ask? Must speed always trump accuracy?